An air conditioning apparatus of this genre in the prior art is typically constructed as disclosed, for example, in Japanese Unexamined Patent Publication No. Hei 02-1113 (relating to a regist processing apparatus) or in Japanese Unexamined Patent Publication No. Hei 04-139345 (relating to a method of and apparatus for supplying an isothermic and isohumid air).
The former typical example above in the prior art is comprised of an air cooling dehumidifier for cooling an absorbed air and dehumidifying the cooled air, a heater for heating the air so dehumidified to a predetermined temperature and a humidifier for humidifying the heated air to a predetermined humidity. And, the said air cooling dehumidifier may be comprised of a compression refrigerator in which a compressed refrigerant is passed through a pipe provided with a multiplicity of fins to cool and dehumidify the air that is brought into contact with those fins.
On the other hand, the latter typical example above in the prior art is comprised of a humidifier for humidifying an absorbed air to a predetermined humidity, an air cooling dehumidifier for cooling and dehumidifying the air so humidified, a heater for heating the humidity adjusted air to a predetermined temperature and a blower for feeding the air through these units. And, this air conditioning apparatus in which the air cooling dehumidifier and the humidifier are large and heavy is installed separately from a spin coater, and is used in a manner in which an ultra-isothermic and ultra-isohumid air is supplied into a cup via a thermally insulated duct or the like.
Incidentally, in the former typical apparatus mentioned above in which the dehumidifier is large and heavy, it has been found that the problem arises that the entire size of the air conditioning equipment in its totality must also be enlarged.
Also, owing to the fact there that it is unable to optionally adjust the air processing capacity of the apparatus, it has been found that if it is forcibly attempted to make any adjustment without regard to such an inability, the cross sectional area of an air duct must be altered.
Furthermore, vibrations are unavoidably created in the above mentioned apparatus due to the fact that use is made of a compressor for the dehumidifier therein. Hence, the problem has always been encountered that a critical measure is required in order to prevent those vibrations from adversely influencing upon a coating that is comprised of a regist or the like.
On the other hand, in the latter typical air conditioning apparatus mentioned above, it has been found that some usage thereof may introduce a thermal disturbance into a thermally insulated duct therein and thus make it difficult to adjust the temperature and humidity therein at a satisfactory precision. Also, as the spin coater is increased in its functions, there is a tendency for its equipment to be more and more large scaled. Thus, there being a tendency for a duct coupling the air conditioning apparatus and the cup together to be lengthened, there has been a fear that the accuracy at which the temperature and the humidity are adjustable may be lowered.
Furthermore, a need for reducing the floor area which the air conditioning apparatus occupies in a clean room has been increasingly demanded because the cost for maintaining the clean room is highly expensive.
These problems may be resolved by installing an air conditioning apparatus that is small sized directly upon the cup of the spin coater and thus by removing the thermally insulated duct that has coupled the air conditioning apparatus and the cup together while eliminating the flour area that has been required for the air conditioning apparatus.
In this respect, a relevant idea has been found in a "regist processing apparatus" as disclosed in Japanese Unexamined Patent Publication No. Hei 02-1113 that is listed above as the former typical example in the prior art.
If this idea is adopted, however, the resultant equipment has been found to be impractical since an amount of condensed water is allowed to drop onto a wafer and so forth because of the structure in which a vertical laminar flow is introduced directly over the said cup to carry out a dehumidification thereof. In addition, the air which is dehumidified by the said air cooling dehumidifier is humidified by the said humidifier that is located immediately below it. Then, the humidified air is heated by an heat exchanger that is located below the said humidifier. There, since the said air cooling dehumidifier is located directly above the said heater, it has been found that there develops, among others, the problem that the efficiency of dehumidification may be deteriorated owing to a heat of radiation that is emitted from the said heater and so forth.
The present invention is provided with the above mentioned problems taken into consideration and has its object to provide an air conditioning apparatus which avoids an amount of condensed water dropping from the air blowing outlet of an air duct, is much small sized as well as much light weighted compared with those utilizing a compression refrigerator in the prior art, eliminates a generation of the vibrations, realizes the implementation of an air conditioning operation that is high in its thermal efficiency while realizing the implementation of an ultra-high-precision air conditioning operation, is capable of readily altering the capacity of a heat exchanger and permits an maintenance operation of the equipment to be readily carried out.